Methanol이 배양된 흰쥐 해마의 신경세포 및 신경교 세포의 성장에 미치는 영향

이정임,조병채,배영숙,이경은 한국독성학회 1996 Toxicological Research Vol.12 No.2

Methanol has been widely used as an industrial solvent and environmental exposure to methanol would be expected to be increasing. In humans, methanol causes metabolic acidosis and damage to ocular system, and can lead to death in severe and untreated case. Clinical symptoms are attributed to accumulation of forrnic acid which is a metabolic product of methanol. In humans and primates, formic acid is accumulated after methanol intake but not in rodents due to the rapid metabolism of methanol. Neverthless, the developmental and reproductive toxicity were reported in rodents. Previous reports showed that perinatal exposure to ethanol produces a variety of damage in human central nervous system by direct neurotoxicity. This suggests that the mechanism of toxic symptoms by methanol in rodents might mimic that of ethanol in human. In the present study I hypothesized that methanol can also induce toxicity in neuronal cells. For the study, primary culture of rat hippocampal neurons and glias were empolyed. Hippocampal cells were prepared from the embryonic day-17 fetuses and maintained up to 7 days. Effect of methanol (10, 100, 500 and 1000 mM) on neurite outgrowth and cell viability was investigated at 0, 18 and 24 hours following methanol treatment. To study the changes in proliferation of glial cells, protein content was measured at 7 days. Neuronal cell viability in culture was not altered during 0-24 hours after methanol treatment. 10 and 100 mM methanol treatment significantly enhanced neurite outgrowth between 18-24 hours. 7-day exposure to 10 or 100 mM methanol significantly increased protein contents but that to 1000 mM methanol decreased in culture. In conclusion, methanol may have a variety of effects on growing and differentiation of neurons and glial cells in hippocampus. Treatment with low concentration of methanol caused that neurite outgrowth was enhanced during 18-24 hours and the numbers of glial cell were increased for 7 days. High concentration of methanol brought about decreased protein contents. At present, the mechanism responsible for the methanol- induced enhancement of neurite outgrowth is not clear. Further studies are required to delineate the mechanism possibly by employing molecular biological techniques.

A novel method of methanol concentration control through feedback of the amplitudes of output voltage fluctuations for direct methanol fuel cells

An, Myung-Gi,Mehmood, Asad,Hwang, Jinyeon,Ha, Heung Yong Elsevier 2016 ENERGY Vol.100 No.-

<P><B>Abstract</B></P> <P>This study proposes a novel method for controlling the methanol concentration without using methanol sensors for DMFC (direct methanol fuel cell) systems that have a recycling methanol-feed loop. This method utilizes the amplitudes of output voltage fluctuations of DMFC as a feedback parameter to control the methanol concentration. The relationship between the methanol concentrations and the amplitudes of output voltage fluctuations is correlated under various operating conditions and, based on the experimental correlations, an algorithm to control the methanol concentration with no sensor is established. Feasibility tests of the algorithm have been conducted under various operating conditions including varying ambient temperature with a 200 W-class DMFC system. It is demonstrated that the sensor-less controller is able to control the methanol-feed concentration precisely and to run the DMFC systems more energy-efficiently as compared with other control systems.</P> <P><B>Highlights</B></P> <P> <UL> <LI> A new sensor-less algorithm is proposed to control the methanol concentration without using a sensor. </LI> <LI> The algorithm utilizes the voltage fluctuations of DMFC as a feedback parameter to control the methanol feed concentration. </LI> <LI> A 200 W DMFC system is operated to evaluate the validity of the sensor-less algorithm. </LI> <LI> The algorithm successfully controls the methanol feed concentration within a small error bound. </LI> </UL> </P>

Development of an advanced MEA to use high-concentration methanol fuel in a direct methanol fuel cell system

Kang, K.,Lee, G.,Gwak, G.,Choi, Y.,Ju, H. Pergamon Press ; Elsevier Science Ltd 2012 INTERNATIONAL JOURNAL OF HYDROGEN ENERGY - Vol.37 No.7

Despite serious methanol crossover issues in Direct Methanol Fuel Cells (DMFCs), the use of high-concentration methanol fuel is highly demanded to improve the energy density of passive fuel DMFC systems for portable applications. In this paper, the effects of a hydrophobic anode micro-porous layer (MPL) and cathode air humidification are experimentally studied as a function of the methanol-feed concentration. It is found in polarization tests that the anode MPL dramatically influences cell performance, positively under high-concentration methanol-feed but negatively under low-concentration methanol-feed, which indicates that methanol transport in the anode is considerably altered by the presence of the anode MPL. In addition, the experimental data show that cathode air humidification has a beneficial effect on cell performance due to the enhanced backflow of water from the cathode to the anode and the subsequent dilution of the methanol concentration in the anode catalyst layer. Using an advanced membrane electrode assembly (MEA) with the anode MPL and cathode air humidification, we report that the maximum power density of 78 mW/cm<SUP>2</SUP> is achieved at a methanol-feed concentration of 8 M and cell operating temperature of 60 <SUP>o</SUP>C. This paper illustrates that the anode MPL and cathode air humidification are key factors to successfully operate a DMFC with high-concentration methanol fuel.

용액에 따른 자동분주기의 분주능력 평가와 분주력 향상 실험

백향미,김영산,윤선희,허의성,김호신,류형기,이귀원,Back, Hyangmi,Kim, Youngsan,Yun, Sunhee,Heo, Uisung,Kim, Hosin,Ryu, Hyeonggi,Lee, Guiwon 대한핵의학기술학회 2016 핵의학 기술 Vol.20 No.2

Purpose In a cyclosporine experiment using a robotic liquid handing system has found a deviation of its standard curve and low reproducibility of patients's results. The difference of the test is that methanol is mixed with samples and the extractions are used for the test. Therefore, we assumed that the abnormal test results came from using methanol and conducted this test. In a manual of a robotic liquid handling system mentions that we can choose several setting parameters depending on the viscosity of the liquids being used, the size of the sampling tips and the motor speeds that you elect to use but there's no exact order. This study was undertaken to confirm pipetting ability depending on types of liquids and investigate proper setting parameters for the optimum dispensing ability. Materials and Methods 4types of liquids(water, serum, methanol, PEG 6000(25%)) and $TSH^{125}I$ tracer(515 kBq) are used to confirm pipetting ability. 29 specimens for Cyclosporine test are used to compare results. Prepare 8 plastic tubes for each of the liquids and with multi pipette $400{\mu}l$ of each liquid is dispensed to 8 tubes and $100{\mu}l$ of $TSH^{125}I$ tracer are dispensed to all of the tubes. From the prepared samples, $100{\mu}l$ of liquids are dispensed using a robotic liquid handing system, counted and calculated its CV(%) depending on types of liquids. And then by adjusting several setting parameters(air gap, dispense time, delay time) the change of the CV(%)are calcutated and finds optimum setting parameters. 29 specimens are tested with 3 methods. The first(A) is manual method and the second(B) is used robotic liquid handling system with existing parameters. The third(C) is used robotic liquid handling system with adjusted parameters. Pipetting ability depending on types of liquids is assessed with CV(%). On the basis of (A), patients's test results are compared (A)and(B), (A)and(C) and they are assessed with %RE(%Relative error) and %Diff(%Difference). Results The CV(%) of the CPM depending on liquid types were water 0.88, serum 0.95, methanol 10.22 and PEG 0.68. As expected dispensing of methanol using a liquid handling system was the problem and others were good. The methanol's dispensing were conducted by adjusting several setting parameters. When transport air gap 0 was adjusted to 2 and 5, CV(%) were 20.16, 12.54 and when system air gap 0 was adjusted to 2 and 5, CV(%) were 8.94, 1.36. When adjusted to system air gap 2, transport air gap 2 was 12.96 and adjusted to system air gap 5, Transport air gap 5 was 1.33. When dispense speed was adjusted 300 to 100, CV(%) was 13.32 and when dispense delay was adjusted 200 to 100 was 13.55. When compared (B) to (A), the result increased 99.44% and %RE was 93.59%. When compared (C-system air gap was adjusted 0 to 5) to (A), the result increased 6.75% and %RE was 5.10%. Conclusion Adjusting speed and delay time of aspiration and dispense was meaningless but changing system air gap was effective. By adjusting several parameters proper value was found and it affected the practical result of the experiment. To optimize the system active efforts are needed through the test and in case of dispensing new types of liquids proper test is required to check the liquid is suitable for using the equipment. 1. 목적 자동분주기를 이용하여 검사한 Cyclosporine검사에서 표준액들이 curve를 벗어나고, 결과값의 재현성이 크게 떨어지는 것이 발견되었다. Cyclosporine검사는 다른 검사와 차이점이 methanol과 전혈을 혼합 후 원심분리 하여 methanol 추출액을 사용하여 검사를 한다는 것이다. 검사 결과 이상의 원인이 methanol 사용에 의한 것으로 파악되어 본 실험을 시작하였다. 본원에서 사용하는 분주기는 Perkin Elmer 사의 Multiprobe II plus 로, 분주하는 액체의 점도, 샘플링 tip의 size, 사용하는 모터의 속도에 따라 여러 설정값을 조정하라고 안내되어 있을 뿐 정확한 지침은 없었다. 이에 사용하는 액체별 분주성능을 측정하고 최적의 분주성능을 위한 설정값을 찾기 위해 연구하였다. 2. 대상 및 방법 분주력 측정을 위해 4가지 용액(water, serum, methanol, PEG 6000(25%))와 $TSH^{125}I$ tracer (515 kBq)을 사용 하였고, 실제 결과 값을 비교하기 위해 2016년 1월에 본원에 검사 의뢰된 Cyclosporine검체 29개를 측정하였다. 4가지의 용액을 multi pipette을 이용하여 각각 $400{\mu}l$ 분주하고 tracer $100{\mu}l$씩을 섞어 용액별로 8개의 검체를 준비하였다. 준비된 sample을 분주기로 $100{\mu}l$씩 분주하여 CPM을 측정하고, 용액별로 CV(%)를 계산하였다. 그리고 분주기의 air gap, 분주속도와 지연시간을 변경한 후 다시 분주하여 측정한 CPM을 CV(%)로 계산하여 설정 값 변경에 따른 CV(%)값의 변화를 측정하여 최적의 설정 값을 찾는다. Cyclosporine검체 29개를 (1)manual검사 (2)기존 설정 값으로 검사 (3)수정한 설정값으로 검사 했을 때의 결과를 비교하였다. 용액별 분주력 평가는 CV(%)를 이용하여 계산하였고, 실제 검사 결과 값의 비교는 manual검사 결과를 기준으로 기존 설정 값으로 검사 했을 때, 수정한 설정 값으로 검사 했을 때의 결과 값을 Difference(%)와 상대오차(%Relative error : %RE)로 비교해 보았다. 3. 결과 4가지 용액과 tracer를 섞어 분주한 CPM의 CV(%)는 water 0.88, serum 0.95, methanol 10.22, PEG는 0.68로 methanol을 제외한 용액들은 1% 이내였으나, methanol은 CPM 차이가 두드러졌다. methanol 분주를 기존 설정 값인 Transport air gap 0에서 2와 5로 변경하여 검사 시 CV(%)는 각각 20.16, 12.54, System air gap 0에서 2와 5로 변경 시 8.94, 1.36으로 나타났다. System air gap 2, Transport air gap 2로 변경 시 CV(%)는 12.96, System air gap 5, Transport air gap 5로 변경 시 1.33 이었고, Dispense speed를 300에서 100으로 변경 시 CV(%)는 13.32, Dispense delay를 200에서 100으로 변경 시는 13.55인 것으로 나타났다. 분주기를 이용하여 기존설정 값으로 검사 시에는 manual검사 결과 값에 비해 평균 99.44%증가 하였고, 상대오차는 93.59%로 나타났다. 수정된 설정 값(System air gap 0에서 5로 변경, 다른 설정은 기존과 동일)으로 검사 했을 때는 manual검사 결과 값에 비해 결과가 평균 6.75% 증가 하였고, 상대오차는 5.10%로 상대오차의 허용기준치 10%에 비하여 양호한 결과가 나왔다. 4. 결론 Transport air gap, Dispense speed, Delay time을 조정하였을 때는 CV(%)가 증가하였고, System air gap을 조정 하였을 때 CV(%)가 현저하게 감소하였다. 실제 검사결과에서도 이를 확인 할 수 있었다. methanol을 이용한 Cyclosporine검사 kit는 올해 2월에 단종이 되었지만, 분주기를 사용함에 있어 용액에 따른 분주성능에 차이가 있을 수 있음을 염두해 두어야 하고 새로운 용액을 분주해야 할때는 미량저울로 분주량을 측정하거나 CPM으로 분주성능을 측정하여 해당 용액이 분주기

Effects of crude methanol recycling on the performance of novel methanol-to-dimethyl ether process

( Chundong Zhang ),김성탁,전기원,곽근재,김용태 한국공업화학회 2016 한국공업화학회 연구논문 초록집 Vol.2016 No.0

Two Methanol-to-Dimethyl ether (MTD) process scenarios 1 and 2 were proposed to develop new MTD processes with improved energy efficiency, by using crude methanol (i.e., water-containing methanol) combined with a water-tolerant K-modified HZSM-5 catalyst. Process modeling was implemented to obtain the quantitative energy analysis results via Aspen Plus software. Both scenarios mainly comprise units of methanol preheating, methanol dehydration, DME separation, methanol separation, and crude methanol recycling. While, the main difference is the way of methanol recycling. The process performance was investigated by varying the recycle ratio or the recycled methanol purity in scenarios 1 and 2, respectively, and compared with the conventional γ-Al2O3 based MTD process. Both Scenarios were shown to be more energy-efficient, and scenario 2 seems to be more beneficial for saving energy as well as CAPEX and OPEX.

Conversion of Methane to Methanol by Methanotroph Methylosinus trichosporium OB3b in the Presence of Various Methanol Dehydrogenase Inhibitors

허동훈,이은열 한국공업화학회 2014 한국공업화학회 연구논문 초록집 Vol.2014 No.1

In this work, we produced methanol from methane using whole cells of Methylosinus trichosporium OB3b as the catalyst and optimized reaction conditions such as addition of methanol dehydrogenase inhibitors, reducing power source and reaction time for an efficient accumulation of methanol. We carried out batch reaction of methane to methanol conversion in the presence of optimized concentration of methanol dehydrogenase inhibitors (potassium phosphate, EDTA, NaCl) and sodium formate as a reducing power source. As a result, we could accumulate methanol in the reactor with high conversion and high productivity. Our result provides an efficient method of producing methanol from methane using methanotroph.

New Methylotrophic Bacterium KJ29의 Methanol Dehydrogenase와 Serine Hydroxymethyltransferase를 이용한 Threonine의 생산에 관한 연구

김경자 한국산업미생물학회 1993 한국미생물·생명공학회지 Vol.21 No.6

토양에서 분리한 통성 메탄올 자화세균중 glycine과 ethanol로부터 threonine을 생산하는 균주를 Methylobacterium sp. KJ29로 명명하고 이 균주의 세포추출물을 이용하여 glycine과 ethanol로부터 threonine 생산의 최적조건을 조사하였다. 이 균주는 methanol뿐 아니라 다른 heterotrophic substrate에서도 잘 자랐으나 methanol에서만 methanol dehydrogenase(MDH) 활성이 나타났으며 이 세포추출물을 이용하여 glycine과 ethanol로부터 threonine을 생산할 수 있었다. 또한 이 균주는 무기 질소원 및 유기 질소원을 이용하여 성장할 수 있었으나 무기 질소원을 이용하여 성장한 균의 세포추출물에서만 MDH 활성이 나타났으며 역시 이 추출물을 이용하여 glycine과 ethanol로부터 threonine을 생산할 수 있었다. 0.5% methanol 농도에서 대수증식기 중기까지 자란 균의 세포추출물에서 MDH 활성이 가장 높았으며 threonine 생산은 45분-60분간의 반응시간에서 가장 높았다. serine hydroyxymethyl-transferase(SHMT) 활성은 탄소원, 질소원에 큰 영향을 받지 않았다. The amino acid threonine was produced from glycine and ethanol in a reaction mixture using cell free extract of the methylotrophic bacterium isolated from soil and identified as mellthylobacterium sp. KJ29. Although the isolate could grow on carbon source other than methanol, only the cell free extract from the cells grown on methanol produced threonine. Methanol dehydrogenase (MDH) activity was present only in the cells grown on methanol when compared to the cells grown on heterotrophic substrates. MDH activity was the highest in the cells grown on 0.5% methanol, mid-exponential growth phase. Methanol dehydrogenase and serine hydroxymethyl-transferase were responsible for the production of threonine from glycine and ethanol.

Multiple steady states in the oxidative steam reforming of methanol

Kim, Jung Hyeon,Jang, Young Shin,Kim, Dong Hyun Elsevier 2018 Chemical engineering journal Vol.338 No.-

<P><B>Abstract</B></P> <P>In the oxidative steam reforming of methanol (OSRM), the partial oxidation of methanol (POM) is commonly assumed to be the main reaction between oxygen and methanol. This assumption was experimentally tested with a commercial Cu/ZnO/Al<SUB>2</SUB>O<SUB>3</SUB> catalyst, and it was found that, in fact, the combustion of methanol (COM) was the main reaction between oxygen and methanol in the OSRM. Furthermore, POM was not an independent reaction but a series of COM and steam reforming of methanol (SRM) reactions. In the presence of oxygen, COM was the main reaction, and, as oxygen was depleted, SRM started and produced hydrogen. Multiple steady states were observed during the temperature cycling of the reactor between 453 and 583 K. The multiplicity was caused by COM and was analyzed in terms of the mass and heat transfer between the catalyst particle and the surrounding gas phase. Although the reactor temperature was kept below 573 K, the upper steady state of the catalyst particle (of the two steady states) was estimated to occur at temperatures above 880 K because of the high heat of combustion and the heat transfer resistance between the catalyst and the surrounding gas phase. When the catalyst was in the upper steady state, the combustion rate was so fast that COM was completed at the reactor inlet and SRM was the main reaction in the reactor. In the lower steady state, on the other hand, the combustion rate was low, and COM was the main reaction in the reactor.</P> <P><B>Highlights</B></P> <P> <UL> <LI> Multiple steady states were observed in oxidative steam reforming of methanol (OSRM). </LI> <LI> Partial oxidation of methanol did not occur in OSRM. </LI> <LI> The reaction between O<SUB>2</SUB> and CH<SUB>3</SUB>OH in OSRM was combustion of methanol (COM). </LI> <LI> Fluid-particle mass and heat transfer resistances caused the multiplicity. </LI> <LI> The Cu-based catalyst was deactivated in OSRM. </LI> </UL> </P> <P><B>Graphical abstract</B></P> <P>[DISPLAY OMISSION]</P>

메탄올 첨가에 따른 Ni 기반 합금의 트라이볼로지 특성 변화에 대한 실험적 연구

최준민,박상문,김영준,김성훈,김혜민,박정언,유정원,이명규,이현우,정구현 한국트라이볼로지학회 2023 한국트라이볼로지학회지 (Tribol. Lubr.) Vol.39 No.2

Currently, the demand for green technologies toward a sustainable future is rapidly increasing due to growing concern over environmental issues. Methanol is biodegradable and can provide clean combustion to reduce sulfur oxide and nitrogen oxide emissions, and therefore it is a candidate fuel for marine engines. However, the effect of methanol on tribological characteristic degradation should be addressed for methanol-fueled engines. In this study, the methanol addition effects on tribological characteristic degradation is experimentally assessed using a pin-on-disk tribo-tester. Ni-based alloy is used as a target material due to its broad applicability as an engine component material. For a lubricant, engine oil with and without methanol are used. The tests are conducted for up to 10,000 cycles under boundary lubrication while the change in friction force is monitored. Additionally, the wear rate is determined based on laser scanning confocal microscope data. An additional test in which methanol is added at regular intervals is performed with an aim to directly observe its effect on friction. Overall, the friction coefficient increases slightly with increasing methanol concentration. Furthermore, the wear rate of the pin and disk increase significantly with methanol addition. The results also indicate that the friction increases instantaneously with methanol addition at the contacting interface. These findings may be useful for better understanding the methanol effect on the tribological characteristics of Ni-based alloys for methanol-fueled engines with improved performance.

Repeated batch methanol production from a simulated biogas mixture using immobilized <i>Methylocystis bryophila</i>

Patel, Sanjay K.S.,Kondaveeti, Sanath,Otari, Sachin V.,Pagolu, Ravi T.,Jeong, Seong Hun,Kim, Sun Chang,Cho, Byung-Kwan,Kang, Yun Chan,Lee, Jung-Kul Pergamon Press 2018 Energy Vol.145 No.-

<P><B>Abstract</B></P> <P>In this study, biological methanol production under repeated batch conditions by immobilized <I>Methylocystis bryophila</I>, using simulated biogas of methane (CH<SUB>4</SUB>) and carbon dioxide (CO<SUB>2</SUB>) as a feed is demonstrated for the first time. The composition of the simulated gas mixtures significantly influenced methanol production by <I>M. bryophila,</I> and in all cases, higher concentrations were achieved than with pure CH<SUB>4</SUB> alone. Under optimum conditions, maximum methanol concentrations of 4.88 mmol L<SUP>−1</SUP>, 7.47 mmol L<SUP>−1</SUP>, and 7.02 mmol L<SUP>−1</SUP> were achieved using the gas mixtures CH<SUB>4</SUB>:CO<SUB>2</SUB> (2:1 ratio), CH<SUB>4</SUB>:hydrogen [H<SUB>2</SUB>, (4:1 ratio)], and CH<SUB>4</SUB>:CO<SUB>2</SUB>:H<SUB>2</SUB> (6:3:2 ratio), respectively, as feed, with a fixed CH<SUB>4</SUB> concentration of 30%. Methanol yield was increased to 7.85 mmol L<SUP>−1</SUP> using covalently immobilized cells and the simulated gas mixture CH<SUB>4</SUB>:CO<SUB>2</SUB>:H<SUB>2</SUB> (6:3:2 ratio). Under repeated batch conditions, immobilized cells produced a significantly higher cumulative methanol concentration (25.75 mmol L<SUP>−1</SUP>) than free cells (15.50 mmol L<SUP>−1</SUP>), using a simulated biogas mixture of CH<SUB>4</SUB>:CO<SUB>2</SUB> (2:1) and eight reuse cycles, suggesting that this mixture can potentially be utilized as a feed for the production of methanol. Furthermore, the effective utilization of low-cost feedstock, derived from natural sources, containing gas mixtures of CH<SUB>4</SUB>:CO<SUB>2</SUB>, CH<SUB>4</SUB>:H<SUB>2</SUB>, or CH<SUB>4</SUB>:CO<SUB>2</SUB>:H<SUB>2</SUB>, constitute an economical and environmentally friendly approach to the reduction of greenhouse gases.</P> <P><B>Highlights</B></P> <P> <UL> <LI> Methanol production was demonstrated by immobilized <I>Methylocystis bryophilla.</I> </LI> <LI> Simulated biogas as feed showed higher methanol production than pure CH<SUB>4</SUB>. </LI> <LI> A maximum methanol production of 7.85 mM was obtained from CH<SUB>4</SUB>:CO<SUB>2</SUB>:H<SUB>2</SUB>. </LI> <LI> Immobilized cells produced a higher cumulative methanol (25.75 mM) than free cells. </LI> </UL> </P>